Under Iranian pressure, Syria appears to be backing away from its decision to send troops to quell militia violence in Beirut's southern suburbs - at least for the time being. Violent clashes continued yesterday despite an announcement late Monday that agreement on a cease-fire had been reached in talks between Syrian and Iranian officials.

After similar talks in Beirut yesterday, Iranian Deputy Foreign Minister Ali Muhammad Besharati said that the Syrians were giving time for political efforts to end the clashes. (Iran and Hizbullah, page 9.)

``Sending the Syrian troops in would not solve the situation, but would complicate it,'' Mr. Besharati said. ``So we worked seriously to restore the status quo. Luckily, our Syrian brothers agreed with our positions and cooperated with us in this.''

The chief of Syrian military intelligence in Lebanon, Brig. Gen. Ghazi Kenaan, questioned about Syria's expressed intention to send the troops in, said that Damascus was not against political efforts to defuse the crisis. He added that the Iranians were displaying ``all seriousness'' in their efforts to halt the fighting.

Last weekend General Kenaan had announced that Syria was preparing to send forces into the suburbs to impose order by force, shooting to kill any unauthorized gunmen found on the streets.

Some 5,000 troops were brought into the city, together with tanks and other armored vehicles. They have taken up positions at the edge of the suburbs, controlling the main access points.

About 200 people have been reported killed since the fighting erupted on May 6 between the Syrian-backed mainstream Amal movement, and the Iranian-sponsored Hizbullah - for some years, rivals within the Shiite Muslim community.

Kenaan said that a four-party committee would be activated shortly to oversee steps to normalize the situation.

The committee, including officials from Syria, Iran, and the two warring factions, was scheduled to meet late Monday and again midday yesterday, but failed to do so because some of the parties did not show up.

The fate of some 15 Western hostages, at least some of whom are believed to be held by Hizbullah or allied groups, was reportedly discussed in weekend talks between Damascus and Tehran.

Other issues are believed to have included Hizbullah's demand, backed by Iran, that its fighters should be allowed to return to southern Lebanon. In fierce fighting with Amal last month, Hizbullah lost many of its positions in the south.

Hizbullah, meanwhile, has driven Amal out of many of its strongholds in the suburbs of Beirut. Only at the northern end of the conurbation, in the neighborhoods of Ghobeiri and Shiah, have the Amal fighters been able to hold on.

Observers say the Syrians are torn between conflicting pressures. If they fail to tame Hizbullah and to take control of the suburbs, their efforts to help get a settlement underway in Lebanon in time for the Lebanese presidential elections later this summer may be derailed.

But if they collide with Hizbullah, they may have to sacrifice their alliance with Iran. That alliance, consolidated in 1982, was primarily motivated by mutual hostility towards Iraq.

``The Syrians have to go in,'' said one Amal source. ``There are so many factors pushing in that direction, including the possibility of an anti-Syrian alliance between Hizbullah and the Palestinians in neighboring camps.''

As happened in February last year, when street battles between Amal and the Druze militia triggered Syrian intervention in West Beirut, there have been numerous calls for a similar move by the Syrians to restore order in the suburbs.